Most mallers, even the smaller mini-malls prefer something like size 40-60 or more. To be in a main market mall, you would need size 630+ or something like that.

I seriously almost peed myself! *lol* You're funny :) It depends on what the shop size requirement is. If you want a requirement of size 20, then you should be a size 100. If you want a requirement of size 100, then 250. Just make sure it is a significant difference, with your shop being the highest.